1. Field of the Invention
This invention pertains to a protective device for a circuit interrupter and, more particularly, it pertains to means for varying the magnetic trip range while maintaining a constant air gap in the magnetic circuit.
2. Description of the Prior Art
Generally, circuit breakers with overcurrent protective devices have external mounting means on the circuit breaker housing such as disclosed in U.S. Pat. No. 3,530,414. Circuit breakers of that type have functioned satisfactorily for responding to such abnormal currents as overcurrents, ground fault currents, and short circuits that occur in an electrical distribution system. However, certain disadvantages result from that type of construction including the inability to vary the magnetic trip ranges such as from five to ten times the nominal rating of a trip unit.